Process of manufacturing nitrate of lime and dicalcium phosphate in a single operation.



- UNIT D s'rATEs PATENT OFFICE.

SAMUEL BEAGOCK, oE CHICAGO, ILLINoI's, ASSIGNOR TO THE SOUTHERN ELECTRO- CHEMICAL COMPA Y, OF NEW YORK, N. Y., a CORPORATION OF NEW JERSEY.

PROCESS OF MANUFACTURING NITRATE OF LIME AND DICAIICIUM PHOSPHATE IN A No Drawing.

Specification of Letters Patent. Application filed September 19, 19 10. Serial lie. 582,777.

SINGLE OPERATION.

Patented-Apr. 1, 1913.

T 0 all whom it mag concern Be it known that I, SAMUEL PEAoocK, a citizen of the United States, residing at Chicagof'in the county of Cook and State of Illinois, have inv'ented certain new and useful Improvements in Processes of Manufacturing Nitrate of Lime and Dicalcium Phosphate ina Single Operation; and I do Generally stated, the process consists in.

treating tricalcium' phosphate when in the form of phosphate rock with gases or vapors containing nltric acid, all as will be now more fully hereinafter described and particularly pointed out in the claims.

As an example of carrying out my process, the procedure may be as follows:

, Phosphate rock is ground to a fineness of about 40 mesh and is then charged into a closed tank, after being mixed with suflicient water to make a thin mud. If desired, a plurality of tanks may be used and so provided with pipes that the gases passing through the thin mud at the bot-tom of onetank will emerge from the to of the same and be then led by suitable piping into the bottom of the succeeding tank and so on until all the nitric acid in the vapors or gases has been dissolved. The construction of the apparatus being of a well known form, it is not here illustrated.

The end of the process will be determined, when all the free lime of the phosphate and one-third of the lime combined with the phosphoric acid is converted into lime nitrate substantially in accordance with the following The dicalcium phosphate CaHPQ, .thus" produced is insoluble in water, while the lime nitrate is soluble and therefore may be separated out by filtration. The dicalcium ammonia especially if it is allowed to suffer a double decomposition with sulfate of ammonia, and the insoluble sulfate of lime is separated out leaving a practically pure nitrate of ammonia in solution. This nitrate of ammonia of course may be readily crystallized to the commercial form.

The special utility of this process may be said to reside in the fact that the dilute nitric acid gases from the electric arc maybe used, as it is not necessary to concentrate these gases for the reaction. The use of such gases of course saves a large item of expense in preparing nitric acid for the manufacture of nitrate of lime, and also by this treatment the phosphate is converted into a form available as a plant food and at practically no cost at all for the nitric acid used. Further, the combined nitric acid is just as valuable as a plant food in the form of nitrate of lime as it is in any other form. By the proc-,

ton of. sulfuric acid at 50 Baum must be used. This sulfuric acid is converted into a 'dition to the above, the average baggin and freight costs in the United States 0 distributing one ton of acid phosphate is $3.00, and as one ton of the material T'Lde by my process is equivalent in available phosphoric acid to three tons as made by the present process, the saving per ton is equivalent to a made by my process costs less than b handsome profit.

A further advantage of my process resides in the fact that the phosphate it produces is not very acid, and it does not therefore destroy the sacks containing the same. Further, it may be mixed with any form of fertilizer materials vwithout danger of losses. That is to say, acid phosphates as made at present cannot be compounded into a complete fertilizer. with either nitrate of soda nor nitrate of lime, two of the most valuable forms of plant food nitrogen, without sufiering considerable losses. Again, as is well known, acid phosphates as made at present are so acid and corrosive, that they effect a serious injury to germinating seeds with which they may come in contact in the soil. The available phosphate made by my process, on the other hand, has no suchinjurious action and may be mixed with the seed itself in planting without suffering any injurious effects at all. Again, the nitrate of lime the present method of manufacturing an for the reason that no lime need be purchased 'for the reaction In other words, in the old process, for every.two equivalents of nitric acid one equivalent of carbonate of lime must be purnitric acid through said water until substan-' tially all of said free lime and one-third of the chemically combined calcium in the tricalcium phosphate is converted into calcium nitrate, substantially as described. 2. The process of producing calcium nitrate and dicalciumphosphate in a single operation and in forms suitable for. plant foods, which consists in finely dividing phosphate rock containing tricalcium hosphate and free lime; immersing said nely' divided rock in water; blowing gases containing nitric acid through said water until substantially all of said free lime and onethird of the chemically combined calcium in the tricalcium phos hate is converted into calcium nitrate; an I in suitably separating the said nitrate from the dicalcium phosphate thus formed, substantially as described.

In testimony whereof, I aflix my signature, in presence of'two witnesses.

SAMUEL PEACOOKe- Witnesses:

' A. H. Bmmooons, Y.

L. A. 'HAMMERSLEY. 

